The invention pertains to the use of a microactuator for micropositioning a disc drive head.
Disc drives are information storage devices that use thin film magnetic media to store data. A typical disc drive includes one or more rotatable discs having concentric data tracks wherein data is read or written. As the disc rotates, a transducer (also known as a "head") is positioned by an actuator to magnetically read data from, or write data to, the various tracks on the disk.
Conventionally, the transducer is attached to a slider having an air bearing surface which is supported adjacent the data surface by a cushion of air generated by the rotating disc. Wires typically connect the transducer on the slider to the disc file read/write electronic circuitry.
The slider is attached on the side opposite the air bearing surface to a suspension assembly, and the suspension assembly is attached to a support arm of a transducer positioning actuator. The slider is maintained in close proximity to, but out of contact with, the data surface of the disc. The suspension assembly provides dimensional stability between the slider and the actuator arm, provides controlled flexiblity in pitch and roll motion of the slider relative to the direction of motion on the rotating disc, and provides resistance to yaw motion.
A load or force is typically applied against the slider by a load beam, and the force is compensated by the cushion of air between the slider air bearing surface and the rotating disc. A gimbal element attached to the load beam is typically attached to the slider by an epoxy binding. The gimbal resiliently supports the slider and allows it to pitch and roll as the slider rides on the cushion of air as it follows the topography of the rotating disc.
In order to accurately read or write data to a disc, the magnetic head must remain closely aligned with the particular track being accessed. As track pitches in the disc drive industry approach 15,000-25,000 tracks per inch, the conventional transducer positioning actuator will be unable to precisely and accurately position the transducer in a specific track on the disc drive.